Thread

1. DELETE/DROP on Columns

   Thomas Swan <tswan@olemiss.edu> — 2000-07-25T16:05:15Z

   	
   I know as far as 7.0.x and back you cannot delete/drop columns from a 
   table.   Is this expected to be in the 7.x series?
   
   
   

2. RE: DELETE/DROP on Columns

   Hiroshi Inoue <inoue@tpf.co.jp> — 2000-07-26T00:17:20Z

   > -----Original Message-----
   > From: Thomas Swan
   > 	
   > I know as far as 7.0.x and back you cannot delete/drop columns from a 
   > table.   Is this expected to be in the 7.x series?
   >
   
   Recently there has been a discussion about this issue.
   Tom proposed a soltution which uses 2(logical/physical)
   attribute numbers. It seems the most reasonable solution
   at present.
   If there's no objection,I would try to implement it according
   to his proposal before 7.1.  
   
   Comments ?
   
   Regards.
   
   Hiroshi Inoue
   Inoue@tpf.co.jp 
   
   

3. RE: DELETE/DROP on Columns

   Hiroshi Inoue <inoue@tpf.co.jp> — 2000-07-27T05:26:20Z

   > -----Original Message-----
   > From: Hiroshi Inoue
   > 
   > > -----Original Message-----
   > > From: Thomas Swan
   > > 	
   > > I know as far as 7.0.x and back you cannot delete/drop columns from a 
   > > table.   Is this expected to be in the 7.x series?
   > >
   > 
   > Recently there has been a discussion about this issue.
   > Tom proposed a soltution which uses 2(logical/physical)
   > attribute numbers. It seems the most reasonable solution
   > at present.
   > If there's no objection,I would try to implement it according
   > to his proposal before 7.1.  
   >
   
   Oops,there remains some problems however.
   They seems to be pretty serious.
   
   1)  Which(logical or physical) attribute number should other
        system tables have ?
        e.g. pg_index,pg_relcheck,pg_attrdef etc ...
        For backend modules,physical attrbiute number is sufficeint
        but client programs which handle metadata would need 
        logical attribute numbers. 
   
   2) How do we handle logical/physical tuple format ?
       For example,there's a function in test/tegress/sql/
       create_function_2.sql which takes a table type input
       parameter and returns setof a table type.
   
       CREATE FUNCTION equipment(hobbies_r)
           RETURNS setof equipment_r
           AS 'select * from equipment_r where hobby = $1.name'
           LANGUAGE 'sql';
   
       This function returns equipment_r tuples of logical format
       which may be different from the physical format which
       is used to store heap tuples once a column is dropped.
       Should input hobbies_r be of logical format also ?
   
   Any comments & suggestions would be appreciated...
    
   Regards.
   
   Hiroshi Inoue
   Inoue@tpf.co.jp